Linux

Linux refers to both the core kernel used in a huge range of computing devices, from
tiny embedded devices to the largest and most powerful mainframe computers available,
and a computer operating system (OS) for desktops, laptops, tablets, phones, servers
and all kinds of embedded devices. It is libre software meaning its program design
(source code) is freely available for anyone to use, copy, modify, sell, rent or publish.
This makes Linux fundamentally different from the Microsoft and Apple operating system,
which do not allow their users any of these freedoms. Several years ago Linux used to
be quite difficult to use but there are now versions of Linux with easy-to-use graphical
user interfaces and a huge amount of software ranging from office-productivity software to
complex scientific software. Linux uses the ALSA sound system to provide support for
multimedia applications.